Phosphate solubilization by soil isolates of Azotobacter chroococcum and their survival at different temperatures

Abstract

Six phosphate solubilizing isolates of A. chroococcum were isolated from the rhizosphere soil of mustard crop and were evaluated for their growth, indole-acetic acid production and phosphate solubilization activity at three different temperatures (30°c, 37°C and 42°C). Our results indicate that all the six isolates of A. chroococcum showed solubilization of tricalciumphosphate (TCP) and rock phosphate (RP) and led to the acidification of the medium at all the three temperatufes. Maximum solubilization was observed by isolates PS 2 and PS 6 at 37°C and 42°C respectively.